| 摘要 |
An optical glass has a refractive index (nd) of 1.60 or over and excellent transmittance and internal quality. The optical glass comprises 0.1-4 mass % of Ta2O5 to total mass of glass calculated on oxide basis, has ratio of 0.95<Ta2O5/(Ta2O5+(ZrO2)+TiO2+Nb2O5+WO3)×5)≦̸1.00, and further comprises SiO2+B2O3+Al2O3+BaO in a total amount of 81% or over. |
